Brain Flashcards
The brain and spinal cord are made up of what?
matter
What are the two kinds of matter?
gray and white
What is the function of gray matter?
receive and process
What kind of structures are made of gray matter?
neuron bodies, dendrites
What is the function of white matter?
send
What kind of structures are made up of white matter?
myelinated axons
What are the characteristics of the brain?
- an organ in the CNS
- located in the head (near the sensory organs)
- 4 regions
- communicates through the spinal cord and 12 pairs of cranial nerves
What are the four regions of the brain?
- cerebrum
- diencephalon
- brainstem
- cerebellum
What protects the brain?
- cranium
- three meninges
- cerebrospinal fluid
- blood-brain barrier
What is a meninge?
brain-covering membranes
What three meninges protect the brain?
- duramater
- arachnoid mater
- pia mater
Duramater
tough outer membrane
Arachnoid mater
web-like, secures the vessels, filled with the CSF
Pia mater
delicate inner membrane fused with the brain
What cell produces cerebrospinal fluid?
ependymal cells
Blood-brain barrier function
prevents the entry of harmful materials
What cell is responsible for forming the blood-brain barrier
astrocytes
What is a ventricle?
interconnected cavities
Ventricles characteristics
- 4 chambers
- connect with the central canal of the spinal cord
- parts contain choroid plexus involved in the production of CSF
Cerebrospinal fluid function
mechanical and chemical protection
What does “mater” mean?
mother
Cortex
an outer layer of an organ
Sulcus
shallow groove
Fissure
deep grove
Gyrus
worm-like fold on the surface
Ganglion
cluster of neuron bodies (GM) in the PNS
Nucleus
cluster of neuron bodies (GM) deep in the CNS
Nerve
bundle of axons (WM) in PNS
Tract
Bundle of axons (WM) in CNS
Cerebrum function
processing of:
- all complex intellectual functions
- voluntary movement
- conscious senses
Complex intellectual functions
reasoning, thoughts, memory
Conscious senses
visual, auditory, olfactory, etc
Structure of cerebrum
two hemispheres separated by the longitudinal fissure
What are the three components of the cerebrum?
- cerebral cortex
- cerebral white matter
- cerebral nuclei
The cerebral cortex is made up of what kind of matter?
gray matter
Structural components of the cerebral cortex
gyri (=folds/hills)
- sulci (= invaginations/valleys)
Cerebral white matter function
forms tracts
Tracts =
pathways
What is an example of cerebral white matter?
corpus callosum that connects left and right hemispheres
Cerebral (basal) nuclei is made up of white kind of matter?
gray matter
Cerebral (basal) nuclei function
regulate movement, muscle tone
The cerebral cortex is divided into how many lobes?
six
What are the lobes of the cerebral cortex?
- frontal lobe
- parietal lobe
- occipital lobe
- temporal lobe
- insular lobe
- limbic lobe
Insular lobe
“island” within the lateral fissure
Limbic lobe
medial “border” of hemispheres
What are the functional areas the cerebral cortex is divided into?
- motor areas
- sensory areas
- association areas
What are the two motor areas?
primary motor cortex and motor speech (broca) area
Primary motor cortex function
voluntary movement
Primary motor cortex location
precentral gyrus
Motor speech (Broca) area function
speech
Motor speech (Broca) area location
left frontal lobe
What are the five sensory areas?
- primary somato sensory cortex
- primary visual cortex
- primary auditory
- primary olfactory cortex
- primary gustatory cortex
Primary somato sensory cortex function
Processes info arriving from:
- proprioceptors
- touch and pressure receptors
- nociceptors
- thermoreceptors
Primary somato sensory cortex location
postcentral gyrus
Primary visual cortex location
occipital lobe
Primary auditory cortex location
temporal lobe
Primary olfactory cortex location
temporal lobe
Primary gustatory cortex location
insula lobe
Proprioceptors
body position, movement
Nociceptors
pain receptors
Thermoreceptors
heat & cold receptors
Gustatory =
taste
The brain combines senses together to construct what?
your reality
Association areas location
adjacent to motor/ sensory areas
Association areas function
interpret, coordinate, integrate with memories
What is an example of an association area?
frontal association area (AA)
Frontal association area =
prefrontal cortex
Frontal AA structure
numerous connections with other parts of the brain
Frontal AA function
determines personality, conscience, learning abilities, judgement, planning
Most cortical areas are replicated on both sides, however, some areas show what?
lateralization
Lateralization
the tendency for some neural functions or cognitive processes to be specialized to one side of the brain or the other
The left side of the brain is responsible for what?
language, numerical, scientific skills
What three functions does the left side of the brain perform?
- verbal memory
- motor speech area (broca’s area)
- Understanding written and spoken language, mathematic comprehension (Wernicke area)
The right side of the brain is responsible for what?
space, patterns, artistic skills, emotional speech
What three functions does the right side of the brain perform?
- memory for shapes (limited language comprehension)
- musical ability
- recognition of faces and spatial relationships
The diencephalon is made up of what?
gray and white matter
Gray matter in diencephalon =
nuclei
White matter in diencephalon =
sensory/motor tracts
What are the three components of the diencephalon?
epithalamus, thalamus, and hypothalamus
What is an example of the epithalamus?
pineal gland
Epithalamus/pineal gland function
hormone melatonin, circadian rhythm
Thalamus composition
composed of many thalamic nuclei
Thalamus functions
- “filters” sensory info before it reaches cortex (becomes conscious) to avoid sensory overload
- Motor areas coordination (there are many of them)
Hypothalamus composition
composed of many hypothalamic nuclei (GM)
Functions of hypothalamus
- master of autonomic NS
- master of endocrine system
- thermoregulation
- Basic emotion
- food intake: sense of hunger
- water intake: sense of thirst
- circadian rhythms
What does “autonomic” mean?
self-regulatory
The hypothalamus is the master of the endocrine system thorough what structure?
the pituitary gland
Thermoregulation aka
thermostat
Basic emotion is a function of the hypothalamus though what system?
limbic nervous system
What are the “basic emotions?”
pleasure, rage, sex drive
The brainstem, midbrain, pons, and medulla oblongata are made up of what?
gray and white matter
Brainstem gray matter function
- forms nuclei
- regulation
Brainstem white matter function
- forms sensory and motor tracts
- send
External gray matter structures of the midbrain
superior colliculus and inferior colliculus
Superior colliculus function
visual reflex cortex
Visual reflex cortex
coordinate movement of eyes, head, torso in response to the visual stimuli
Inferior colliculus
auditory reflex center
Auditory reflex center
coordinate movement of eyes, head, torso in response to the auditory stimuli
Internal gray matter structures of the midrbain
red nucleus and substantia nigra
Red nucleus (motor control) function
involuntary motor control, like in maintenance of posture
Substantia nigra function
neurotransmitter dopamine
Dopamine function
movement control, emotions, pleasure/pain
Dopamine loss results in what?
Parkinson’s disease
What are some of the most common symptoms of Parkinson’s disease?
resting tremors, stiffness,
Pons regulatory nuclei (GM centers) of importance
pontine respiratory center and superior olivary nucleus
Pontine respiratory center function
responsible for breathing
Superior olivary nucleus function
responsible for sound localization
Medulla oblongata gray matter forms what?
autonomic nuclei
What are the autonomic nuclei present in the medulla oblongata?
- cardiac center
- vasomotor center
- medullary respiratory center
- protective center
- digestive center
Cardiac center function
controls the heart
Vasomotor center function
controls vessels
Medullary respiratory center function
controls breathing
Protective center function
coughing, sneezing, gagging, vomiting etc.
Digestive center function
salivation, swallowing, etc.
What structure coordinates the activities of the medulla oblongata nuclei centers in order to maintain homeostasis?
hypothalamus
What structures make up the cerebellum?
- 2 hemispheres
- cerebellar cortex
- arbor vitae
- cerebellar nuclei
Cerebellar cortex
outer gray matter with folds, folia
Arbor vitae composition
white matter
Cerebellar nuclei composition
inner gray matter
Cerebellum functions
- elevates, “fine-tunes” movement = smooth + precise
- stores memories of previously learned movements
- balance and posture
How does the cerebellum control the fine-tune movements?
cerebellum receives input from motor pathways and sensory pathways
How does the cerebellum perform balance and posture?
collects proprioceptive information thus adjusting muscle tone
What are the two functional brain systems?
reticular formation and limbic system?
What is the reticular formation?
small clusters of gray matter interspersed among small bundles of white matter.
Where is the reticular formation located?
parts of thalamus, brain, stem, and superior spinal cord
What are the two functions of the reticular formation?
motor coordination and sensory functions
Reticular formation: motor coordination
responsible for motor coordination between different parts of the brain involved in the regulation of movement of the skeletal, smooth, cardiac muscles
What system is derived from the sensory function of the reticular formation?
Reticular activating system (RAS)
Reticular activating system
uses passing sensory signal to activate cortex (state of consciousness)
What type of sensory signal does not affect the RAS?
olfactory signals (smell)
comaWhat is the result of the inactivation of RAS?
sleep
What is the result of damage to the RAS?
coma
What does “limbus” mean?
border
Limbic system is also known as what?
the emotional brain
What five structures make up the limbic system?
- basal nuclei
- olfactory bulb + olfactory cortex
- amygdala
- hippocampus
- hypothalamus
Basal nuclei function
responsible for pleasure/aversion, motivation, and addiction
Olfactory bulbs + olfactory cortex function
emotions associated with odors
Amygdala function
responsible for the self-preservation emotions:
- fear
- aggression
Hippocampus function
conversion of short-term memories into the long-term memory
Hypothalamus function in limbic system
coordination of various limbic system components